The present invention relates to a core yarn manufacturing machine and a core yarn manufacturing method which manufacture the core yarn like a true twist by a hollow guide shaft member and the whirling flow which acts upon the tip section of the hollow guide shaft member, and especially to a core yarn manufacturing machine and a core yarn manufacturing method capable of carrying out automatic yarn pick-up.
Core yarn manufactured by a hollow guide shaft member and a whirling flow which acts upon the tip section of the hollow guide shaft member, includes multifilament yarn of a synthetic fiber, such as polyester, as a core fiber, and has a fiber bundle of cotton or the like wound around the core fiber. The core fiber cannot be seen from the surface, and the core fiber is concentrated in the center.
The core yarn manufactured by using such whirling flow is especially characterized in that the thickness of the core fiber can be made more than 50% and the torque (the level of the yarn shrinking in the axis direction) is small, compared to core yarn manufactured by a ring spinning frame.
The core yarn manufactured by the ring spinning frame is formed to be a core yarn like a true twist by being twisted while whirling the yarn around the winding bobbin. However, the core fiber can be seen from the surface and the core fiber exists also in the areas around the center.
Therefore, there is the core yarn manufacturing machine for manufacturing core yarn like a true twist, comprising air-typed spinning unit which is fed with core fiber and the drafted fiber bundle.
The spinning unit is comprised of a hollow guide shaft member wherein the yarn passage is formed in the axis direction, and a whirling flow generating nozzle which generates whirling flow to the tip section of the hollow guide shaft member.
The core yarn manufacturing machine manufactures core yarn by winding the fiber bundle guided into the spinning unit after being drafted, around the core fiber fed to the spinning unit along with the fiber bundle at the tip section of the hollow guide shaft member.
However, the core yarn manufacturing machine adopting the hollow guide shaft member and the whirling flow which acts upon the tip section of the hollow guide shaft member, were not considered to carry out automatic yarn pick-up of the core yarn, including the automatic feeding of the core fiber.
The core yarn manufacturing machine forms a core yarn like a true twist, by the fiber bundle being sucked into the yarn passage, and the reversing fiber separated from the fiber bundle, being wound around the core fiber. Therefore, when attempting the automatic yarn pick-up under the same condition as the normal spinning operation, the force to suck in the fiber bundle into the yarn passage of the hollow guide shaft member, is not produced only by the whirling flow of the whirling flow generating nozzle. Thus, the fiber bundle cannot be exhausted from the yarn outlet of the spinning unit as a yarn.
The object of the present invention is to provide a core yarn manufacturing machine and a core yarn manufacturing method capable of carrying out automatic yarn pick-up of the core yarn like a true twist.
The present invention was made in consideration to the object mentioned above. The present invention is a core yarn manufacturing machine comprising a spinning unit constituting a hollow guide shaft member wherein the yarn passage is formed in the axis direction, and a whirling flow generating nozzle for applying whirling flow to the tip section of the hollow guide shaft member; wherein a core yarn is manufactured by winding the fiber bundle drafted and guided into the spinning unit, around the core fiber fed to the spinning unit, along with the fiber bundle in the tip section of the hollow guide shaft member; wherein the core yarn manufacturing machine comprises a suction force producing means for producing the suction force toward the interior of the yarn passage from the entrance of the hollow guide shaft member, a core fiber feeding apparatus for feeding the core fiber to the spinning unit, and a control device for controlling the operation and non-operation of the whirling flow generating nozzle, the operation and non-operation of a suction force producing means, and the operation and non-operation of the core fiber feeding apparatus.
According to the composition described above, a strong suction force is generated toward the interior of the yarn passage from the yarn entrance of the yarn passage, allowing the core fiber and the fiber bundle to be taken in to the yarn entrance. As a result, automatic yarn pick-up of the core yarn from the yarn outlet can be carried out by passing through the yarn passage.
The present invention is the core yarn manufacturing machine wherein the suction force producing means is a compressed air injecting nozzle which injects compressed air into the yarn passage of the hollow guide shaft member. According to this composition, a strong suction force can be produced to the entrance of the hollow guide shaft member, with simple composition.
The present invention is a core yarn manufacturing machine wherein the suction force producing means is a compressed air injecting nozzle which injects compressed air into the yarn passage of the hollow guide shaft member. According to this composition, a strong suction force can be produced to the entrance of the hollow guide shaft member.
The present invention is the core yarn manufacturing machine wherein the injection pressure of the whirling flow generating nozzle can be switched between high and low according to the signal from the control device. As a result, the success rate of the yarn pick-up is improved by minimizing the whirling force of the core fiber and the fiber bundle which are moved by the whirling flow of the whirling flow generating nozzle, in proximity to the entrance of the hollow guide shaft member.
According to the composition described above, the core fiber and the fiber bundle can be sucked in by generating strong suction force toward the interior of the yarn passage from the yarn entrance of the yarn passage. As a result, automatic yarn pick-up of the core yarn from the yarn outlet can be carried out by passing through the yarn passage.
The present invention is the core yarn manufacturing method wherein the whirling flow generating nozzle carries out low pressure injection first when carrying out yarn pick-up of the core yarn, and can switch to high pressure injection after the core yarn passes through the yarn passage of the hollow guide shaft member and is exhausted from the yarn outlet of the spinning unit.
According to the composition described above, the whirling force which moves the core fiber and the fiber bundle in proximity to the entrance of the hollow guide shaft member, is minimized and the suction force of the suction force producing means acts more efficiently. Therefore, the success rate of the yarn feeding of the core fiber and the fiber bundle to the yarn passage improves, and the success rate of the yarn pick-up from the yarn passage also improves.